1. Field of the Invention
The present invention relates to a detecting method and device for capacitive touch screens, and more particularly, to a detecting device and method for capacitive touch screens that improves the signal-to-noise ratio by switching between frequencies.
2. Description of the Prior Art
A capacitive touch screen determines the locations of touches made by a human body thereon based on changes in detected signals due to its capacitive coupling with the body. When the human touches the screen, noise surrounding the human body also adds to the capacitive coupling between the human body and the capacitive touch screen, and thus causing changes in the detected signals. Moreover, since noise is not constant, it cannot be easily determined. When the signal to noise ratio (S/N ratio) is relatively small, a touch may not be detected, or the location of the touch may not be accurately detected.
From the above it is clear that prior art still has shortcomings. In order to solve these problems, efforts have long been made in vain, while ordinary products and methods offering no appropriate structures and methods. Thus, there is a need in the industry for a novel technique that solves these problems.